CVE-2026-48125
UAParser.js: Unbounded `Sec-CH-UA-Model` parsing can trigger ReDoS in `withClientHints()`
Description
UAParser.js is a JavaScript library to detect browsers, operating systems, CPUs, and devices from user-agent data. From 2.0.1 until 2.0.10, a regular expression denial-of-service vulnerability exists when using the Client Hints API. By sending a crafted Sec-CH-UA-Model header to an application that calls UAParser(headers).withClientHints(), an attacker can cause excessive CPU time due to catastrophic backtracking in the device regex because Client Hints values are copied without the UA_MAX_LENGTH limit used for User-Agent values. This issue is fixed in version 2.0.10.
INFO
Published Date :
July 14, 2026, 9:16 p.m.
Last Modified :
Aug. 6, 2026, 6:25 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update UAParser.js to version 2.0.10 or later.
- Ensure Client Hints API uses UA_MAX_LENGTH limit.
- Review regex handling for User-Agent data.
- Test application for stability after update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-48125.
| URL | Resource |
|---|---|
| https://github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d76673e6d14fc5 | Patch |
| https://github.com/faisalman/ua-parser-js/releases/tag/2.0.10 | Release Notes |
| https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 | Exploit Vendor Advisory |
| https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48125 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-48125
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48125 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48125 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 06, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:ua-parser-js_project:ua-parser-js:*:*:*:*:*:node.js:*:* versions from (including) 2.0.1 up to (excluding) 2.0.10 Added Reference Type GitHub, Inc.: https://github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d76673e6d14fc5 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/faisalman/ua-parser-js/releases/tag/2.0.10 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 15, 2026
Action Type Old Value New Value Added Reference https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599 Added SSVC {'id': 'CVE-2026-48125', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-15T12:55:17.247452Z'} -
New CVE Received by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'faisalman', 'product': 'ua-parser-js', 'versions': [{'status': 'affected', 'version': '>= 2.0.1, < 2.0.10'}]}] Added Description UAParser.js is a JavaScript library to detect browsers, operating systems, CPUs, and devices from user-agent data. From 2.0.1 until 2.0.10, a regular expression denial-of-service vulnerability exists when using the Client Hints API. By sending a crafted Sec-CH-UA-Model header to an application that calls UAParser(headers).withClientHints(), an attacker can cause excessive CPU time due to catastrophic backtracking in the device regex because Client Hints values are copied without the UA_MAX_LENGTH limit used for User-Agent values. This issue is fixed in version 2.0.10. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-400 Added CWE CWE-1333 Added Reference https://github.com/faisalman/ua-parser-js/commit/90354d3458495628b1d3ba68a9d76673e6d14fc5 Added Reference https://github.com/faisalman/ua-parser-js/releases/tag/2.0.10 Added Reference https://github.com/faisalman/ua-parser-js/security/advisories/GHSA-9h5v-pfqq-x599